Apparatus for applying two-part surgical fasteners

ABSTRACT

Apparatus for applying at least one row of two-part surgical fasteners to body tissue, each surgical fastener having a pronged fastener portion for piercing body tissue, and an aperture retainer dimensioned and configured for engaged reception of the pronged fastener portion in interference fit therewith for gripping the body tissue therebetween. The apparatus includes means for holding a plurality of the fastener portions in generally aligned relation, means spaced from the fastener portion holding means for gripping body tissue therebetween and for releasably holding a plurality of the retainers in generally aligned relation and positioned opposite the fasteners when the body tissue is positioned therebetween. Means is provided for sequentially advancing the pronged fastener portions toward the apertured retainers to cause the fastener portions to pierce the body tissue and to be received within the apertures of the retainers in engaged interference relation so as to cause the fastener portions and the retainers to be engaged while gripping the body tissue therebetween. In the preferred embodiment a knife edge is provided to cut the body tissue midway between opposed pairs of rows of the fasteners as the fasteners are applied. A method for applying two spaced apart pairs of rows of the fasteners to body tissue on the apparatus of the invention is also disclosed.

This is a continuation of copending application Ser. No. 07/794,596,filed Nov. 14, 1991.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus for applying surgical fastenersand more particularly, to a fastener applying apparatus having animproved fastener cartridge and holder for the retainer portion oftwo-part surgical fasteners.

2. Background of the Prior Art

In some surgical operations it is necessary to adjoin two hollow bodyorgans alongside each other, with their longitudinal axes positionedgenerally parallel to each other, and to effect a longitudinal cutthrough the contacting circumferential walls of the two organs in orderto open them to each other. After joining the two organs theyessentially constitute a single hollow chamber along the length of thecut. Correspondingly, the circumferential portions of the two adjoiningorgans on each lateral side of the cut must be sutured by at least oneline of "stitches" in order to maintain the integrity of the union.

Instruments for this purpose are known in the art, and are described inU.S. Pat. Nos. 3,079,606, 3,490,675 and 3,499,591. Such instruments aregenerally referred to as linear cutting staplers and include twoelongate fingers which are respectively insertable into each organ froman open end thereof such that the two fingers have the adjoining wallsof the adjacent organs therebetween. Further examples of suchinstruments are disclosed in commonly assigned U.S. Pat. Nos. 4,429,695and 4,520,817. The disclosures of these two last mentioned patents areincorporated herein by reference.

One of the fingers includes a disposable cartridge carrying a pluralityof staples arranged in at least two lateral rows while the other fingerincludes an anvil for curling the staple legs into hook form upon beingdriven against the anvil. The stapling operation is effected by a pusherdevice which travels longitudinally along the cartridge carrying fingerextending into one organ. The pusher mechanism acts simultaneously uponthe staples at corresponding longitudinal positions in each lateral row,but successively acts upon the staples along the rows. For example, iftwo laterals rows of staples are provided, each row comprising twentystaples, the pusher means acts upon two staples at a time, one in eachrow, and successively acts upon each succeeding pair of staples.

Immediately behind the pusher means and laterally positioned between thestaple rows is a knife member which severs the facing adjoining walls ofthe two organs to thereby longitudinally open the two organs to eachother between the rows of staples.

Up to the present these devices were limited to applying metal staples.Two-part absorbable fasteners, such as those used in devices describedin U.S. Pat. No. 4,665,916, hereby incorporated by reference, have beenlimited to devices which apply all of the fasteners simultaneously.Indeed, the retainer members of such absorbable fastener devicestypically have been constructed as a web of retainers interconnected byflexible or frangible members. See, for example, U.S. Pat. No.4,589,416. Devices of the type shown in the aforementioned U.S. Pat.Nos. 3,079,606; 3,490,675 and 3,499,591, on the other hand, employ anactuating cam bar which travels substantially perpendicularly to thedirection of fastener motion to effect sequential placement of staples.

Up to the present, applying two-part absorbable fasteners withinstruments of the type disclosed in U.S. Pat. Nos. 3,079,606; 3,490,675and 3,499,591 has not been possible due in part to the peculiardifficulties inherent in aligning the separate fasteners and retainers.The present invention relates to an apparatus which successfullycombines a system of applying such fasteners sequentially while cuttingthe tissue and effecting complete closures.

SUMMARY OF THE INVENTION

An apparatus is disclosed for applying at least one row of two-partsurgical fasteners, each surgical fastener having a pronged fastenerportion and a retainer, which comprises means for holding the fastenerportions of the two part surgical fasteners, a retainer cartridge havingmeans for holding a plurality of retainers in positions opposite thefastener portions, a plurality of retainer mounting elements located inthe retainer cartridge for releasably engaging and holding theretainers. The fastener portions and retainers are arranged inlongitudinal alignment with the axis of the apparatus, and the fastenerportions are sequentially driven into engagement with their respectiveretainers, and means for sequentially driving the fastener portions ofthe two part fasteners into engagement with the respective opposedretainers.

The retainer mounting elements are slidably mounted within a lowerchannel in the retainer cartridge and arranged to release theirrespective retainers in response to the engagement of the fastenerportions with their respective retainers. Further, the retainer mountingelements each comprise a base portion and at least one upright post forengaging an aperture in the retainer and frictionally holding theretainer. A surface portion of the upright post is preferably inclinedon at least one vertical side and backstop means is provided for bracingthe retainers when engaging with the fastener portions. The backstopmeans comprises a horizontal shelf portion of the cartridge upon whichthe retainers at least partially rest. The lower and upper channels havevertical side walls, and the lower channel is of lesser width than theupper channel and is located below the upper channel thereby forming atleast one shelf portion. The lower channel has a plurality of verticalguide rails and the retainer mounting elements each have at least onevertical notch for cooperating with a respective one of the verticalguide rails. Preferably the two-part surgical fasteners arebio-absorbable and the apparatus is adapted to fasten body tissuetherewith.

The preferred embodiment of the apparatus comprises a two part framehaving separable sections capable of releasable attachment to each otherand each having an elongated finger portion. A fastener carryingcartridge is mounted along one of the finger portions and carries aplurality of the fastener portions, and a retainer carrying cartridge ismounted along the other finger portion opposite the fastener cartridgeand carries a plurality of the retainer members positioned opposite thefastener portions. A pair of cam bars is positioned for slidablemovement distally and proximally within the frame for sequentialengagement with the fastener pushers.

A generally U-shaped shoe plate is provided between each fastener andretainer cartridge and the respective channel members of the frame. Eachshoe plate defines a channel for reception of a respective shoeassociated with the cam bars. The respective shoes prevent separation ofthe frame members when the cam bars are advanced a predetermineddistance due to the entry of said shoes associated therewith into thechannels defined by the shoe plates.

A method is disclosed for applying at least one row of two-part surgicalfasteners, each surgical fastener having a pronged fastener portion anda retainer, comprising, holding the fastener portions of the two-partsurgical fasteners, releasably holding a plurality of retainers inpositions opposite the fastener portions, and sequentially driving thefastener portions of the two-part fasteners into engagement with theirrespective opposed retainers. Each surgical fastener has a prongedgenerally U-shaped fastener portion, and an apertured retainerdimensioned for engaged reception of the fastener portion. Preferablythe method comprises holding a plurality of the fastener portions,releasably holding a plurality of the retainers in positions oppositethe fastener portions such that the apertures thereof face the prongedportions of the fastener portions, and sequentially driving the fastenerportions of the two-part fasteners toward the retainers so as to causethe pronged portions to be engagably received within the apertures ofthe retainers. Preferably two rows of fastener portions and matingretainers are provided.

According to the method, body tissue to be fastened is positionedbetween the rows of fastener portions and retainers such thatsequentially driving the fastener portions toward the retainers causesthe fastener portions to be driven through the tissue so as to grip thetissue between the fastener portions and the retainers. The methodfurther comprises cutting the tissue while driving the fastener portionstoward the retainers.

The method is preferably accomplished on an apparatus which permitsrelease of the tissue after the fastening and engagement of the two-partfasteners is complete.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described hereinbelow withreference to the drawings wherein:

FIG. 1 is a perspective view of the apparatus for applying two-partsurgical fasteners constructed according to the present invention;

FIG. 2 is an exploded perspective view of the apparatus of FIG. 1,illustrating the two half sections of the fastener applying mechanism;

FIG. 3 is an exploded perspective view with parts separated, of thefastener cartridge and associated handle mechanism;

FIG. 4 is an exploded perspective view with parts separated, of theretainer cartridge and associated handle mechanism;

FIG. 5 is an exploded perspective view of the operable portions of theapparatus of FIG. 1, illustrating the mechanism for advancing cammingfingers and a tissue cutting blade to secure the two partfastener/retainer and for cutting adjacent tissue;

FIG. 6 is a view, partially in cross-section, taken along lines 6--6 ofFIG. 1 illustrating the finger operated pad and related mechanism foradvancement of the tissue cutting knife and fastener closure cam bars;

FIG. 7 is a cross-sectional view taken along lines 7--7 of FIG. 1illustrating the finger operated advancement mechanism for cuttingtissue and effecting closure;

FIG. 8 is a view, partially in cross-section, taken along lines 8--8 ofFIG. 1, illustrating the attachment mechanism for securing the two halfsections of the apparatus together;

FIG. 9 is a cross-sectional view taken along lines 7--7 of FIG. 8,illustrating the attachment mechanism of FIG. 8;

FIG. 10 is a cross-sectional view taken along lines 10--10 of FIG. 1,illustrating the relative positions of the fasteners and retainers priorto firing the apparatus;

FIG. 11 is a view similar to FIG. 10, illustrating the fasteners andretainers after firing the apparatus;

FIG. 12 is a more detailed exploded perspective view of a two-partsurgical fastener shown with the retainer mounting element and theretainer holding cartridge of the present invention;

FIGS. 13A, 13B, 13C and 13D are respectively, plan elevational, bottom,and cross-sectional views providing further details of the retainerholding cartridge;

FIGS. 14A and 14B are plan views of left hand, and right hand retainermounting elements, respectively;

FIG. 15 is a side elevational view of the retainer mounting element ofFIG. 14B;

FIG. 16A illustrating in cross-sectional view, further details of theretainer portion of a two-part surgical fastener positioned on aretainer mounting element in the pre-fired position;

FIG. 16B illustrates in cross-sectional view, the retainer portion of atwo-part surgical fastener positioned on a mounting element in the firedposition; and

FIG. 17 illustrates in cross-sectional view, the two part surgicalfasteners being joined in an apparatus employing the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1, there is illustrated a perspective viewof the apparatus 10 for applying two-part fasteners constructedaccording to the present invention. The apparatus 10 includes halfsections 12 and 14 as shown, which are adapted to be clamped together ina manner to be described. The two half sections 12 and 14 are shown inperspective view in FIG. 2 and each half section is shown with partsseparated in FIGS. 3 and 4.

Referring now to FIG. 3, half section 12 for receiving and supportingfastener cartridge 16 is shown. The handle section includes body 18,which receives fastener channel 20. Fastener cartridge 16 receives twostaggered rows of U-shaped fasteners. A first pair of rows of fastenerportions such as fasteners 22 is disposed on one side of a knife bar 32and is provided with corresponding fastener pushers 24. A second similarstring of a pair of U-shaped fasteners 26 are advanced by correspondingpushers 28 on the other side of knife bar 32. Fasteners 22 and 26 aremaintained within suitable spaces 16a provided in cartridge 16 which aredimensioned to frictionally support the fasteners until ejected by thepushers. Shoe plate 30 is provided as shown for slidable reception of afastener shoe 44.

Referring further to FIG. 3, knife bar 32 is flanked by cam bars 34 and36 which are connected to bar retainer 38 which in turn is connected tofinger pad 40 for finger operated motion of the cam bars 34,36. Aretainer spring 42 is provided for engagement with the pivoted handle ofthe retainer half section (to be described below) to retain theapparatus in the locked condition when the handle is closed. Fastenershoe 44 is attached to knife bar 32 at tab 32a on the fastener side andretainer shoe 46 is attached to knife bar 32 at tab 32b on the retainerside as shown. As will be described in further detail, fastener shoe 44and retainer shoe 46 slide within respective shoe plates 30,50 (FIGS. 3and 4) and serve to secure the two half sections 12,14 together afterthe knife bar is advanced a predetermined amount in order to preventseparation of the half sections. Also, the shoes 44,46 and the shoeplates serve to control the gap between the fastener cartridge and theretainer cartridge and thus the relative positions of the fastenerportion and the retainer portion. Knife 35 having a sharp knife edge isattached to knife bar 32 as shown for cutting tissue simultaneously withthe fastening operation. Knife 35 lags the cam bars a small distance,i.e. about 5 mm.

Referring now to FIG. 4 the retainer half section 12 is illustrated withparts separated. Retainer channel 48 is provided with retainer shoeplate 50 and retainer cartridge 47 for supporting two staggered rows ofretainers 52 and 54, with associated retainer holders 56 and 58. Theretainers are each precisely positioned opposite a respective fastenerwhen the half sections of the apparatus are assembled.

Handle clamp 60 is pivotally attached to channel 48 via pin 62 with leafspring 65 positioned therebetween to resiliently bias handle clamp 60away from retainer channel 48. Handle cap 64 is attached to handle clamp60 and nose cap 66 is provided as shown at the distal end of cap 64.

Referring now to FIG. 5, the motion of knife bar 32 and associated cambars 34,36 is illustrated. When finger pad 40 is moved distally by thesurgeon, the distal sloped surfaces 64,66 of cam bars 34,36 engage thecorresponding proximal surfaces 68a and 70a (not shown in FIG. 5) offastener pushers 24 and 28 (not shown in FIG. 5), causing movement ofthe pushers in a direction substantially perpendicular to movement ofcam bars 34, 36 and engagement with fasteners 22 and 26. This movementcauses the fasteners to move transversely toward corresponding retainerswhich are at this time, secured in upstanding relation to retainermonitoring elements shown as retainer holders 56 and 58 (holder 58 notshown in FIG. 5) by insertion of upstanding posts 72,74 into theapertures 76,78 on the side of retainers 52,54 opposite the fastenerside. Similarly, the retainer holders 56,58, prior to firing thefasteners, are positioned within cartridge 47 such that the top surfacesof the posts 72,74 are approximately at the level of the surfaces 57a ofthe side rails 57 of retainer cartridge 47 as shown in FIGS. 5 and 10.The retainer holders 56,58 are dimensioned to be positioned betweenrails 57 of the cartridge 52 with slight frictional fit to maintain theposition shown in FIG. 10. This position permits the movement of holder55 toward the lower surface 59 of cartridge 52 during firing such thatposts 51 enter central apertures 53 of the holders 56 to assist incontinued alignment of the fastener retainers 26 with the fasteners 27.Additional details relating to the fasteners and retainers will beprovided in conjunction with FIGS. 12-17.

Referring now to FIGS. 6 and 7 the finger operated pad and associatedmechanism for advancing the tissue cutting knife and fastener closurecam bars are shown. FIG. 6 is a cross-sectional view taken along lines6--6 of FIG. 1, and FIG. 7 is a cross-sectional view taken along lines7--7 of FIG. 6. Pad 40 is connected to bar retainer 38 by stem 39 withcam bars 34,36 and knife bar 32 connected at their proximal end portionsto bar retainer 38 (see also FIG. 3). The proximal end portion 49 ofretainer channel 48 has a cut-out portion 51 (FIGS. 4 and 6). A pin 21is inserted in fastener channel 20 and positioned within cut-out portion51 to facilitate alignment of the retainer channel 48 with fastenerchannel 20 as shown in FIG. 6. Further alignment of the half sections12, 14 of the apparatus is provided by the side walls 20a, 48a of thechannels 20,48, respectively, as shown in FIG. 7, wherein the side walls48a of channel 48 are slidably and snugly positioned within sidewalls20a of channel 20 when the half sections 12, 14 of the apparatus areassembled.

Referring now to FIG. 8, the mechanism for locking the half sections12,14 is illustrated in cross-section. Handle clamp 60 (shown in FIG. 4)is pivotally mounted to retainer channel 48 as described previously, andincludes distal clamp section 60a having locking fingers 60b. Theselocking fingers are dimensioned and configured to engage shoulders 31aof anchor 31 attached to fastener cartridge 21 (also see FIG. 3) whenthe half sections 12,14 are assembled in face to face relation andhandle 64 and clamp 60 are pivotally advanced toward half section 14.This movement causes engagement between locking fingers 60b andshoulders 31a of anchor 31 to secure the half sections 12,14 together.

Referring now to FIG. 8, a safety feature of the present apparatus isillustrated. The knife bar 32 includes fastener shoe 44 attached to thedistal end portion 32a as shown, and retainer shoe 46 attached to thedistal end portion 32b as shown (also, see FIG. 3). When the halfsections 12,14 are fully assembled and handle 64 and clamp 60 are closeddistal movement of finger pad 40 is made possible, causing correspondingdistal movement of cam bars 34,36 and knife bar 32. With this motion,retainer shoe 46 and fastener shoe 44 slide distally within therespective channels defined by fasteners shoe plate 30 and retainer shoeplate 50. It will be readily appreciated that any distal movement offinger pad 40 will cause the shoes 44,46 to enter their respectivechannels and prevent separation of the half sections 12,14 in the eventhandle 64 and clamp 60 are inadvertently urged toward the unlockedposition. Continued distal motion results in transverse movement offastener pushers to cause sequential closure of the fasteners with theretainers.

FIG. 10 illustrates the half sections 12,14 in the pre-fired positionsand FIG. 11 illustrates the half sections 12,14 of the apparatus afterthe fasteners are fired and the tissue is cut. Similarly, FIGS. 12, 13and 14 illustrate the fastener and retainer system in exploded view.Referring now to FIG. 10 in conjunction with FIGS. 1 and 2, a crosssection of the fastener system illustrates fastener half section 14 withexemplary fastener 22 and half section 12 with exemplary retainer 54.Retainer holder 58 secures retainer 54 in precisely correct alignedposition by insertion of posts 51 into the apertures of the retainer onthe side opposite the fastener entry side. FIG. 11 illustrates the halfsections shown in FIG. 10 after firing the finger activated finger pad40 which cause the following simultaneous actions:

1) knife 32a cuts tissue as shown.

2) fastener cam bars 34, 36 sequentially engage fastener pushers 24, 28causing movement of the fasteners 22, 26 toward retainers 52, 54 suchthat the fasteners engagably enter the retainer openings andsimultaneously push retainer holders 56 deeper into the cartridge 50while releasing the hold which holders 56 previously had on retainers52, 54. This position causes the resilient spear shaped leading edge ofthe absorbable two part fasteners 22,26 to be securely retained withinthe retainers 52, 54 which are dimensioned and shaped for correspondinglocked interference fit with the fasteners. While this fastening actionoccurs the retainers 52,54 are supported on surfaces 57a of sideshelves--or rails--57 as shown in FIG. 11. Thus, the tissue halvesbecome securely fastened by the dual staggered rows of fasteners on eachside of the cut and the organs are joined to form a single hollowchamber.

The downward motion of the fasteners is aligned precisely with theretainer openings due to the alignment of the retainers as secured bythe holders 54 and the uniform downward motion provided by the fastenerpushers 24. The second (or distal) sloped surface 68b of the samepusher, as shown in FIG. 4 facilitates proximal movement of cam bars34,36.

Referring now to FIGS. 12-17, the inventive fastener and retainer systemconstructed according to the present invention is shown in explodedperspective views providing additional details of the fastener lockingsystems. For convenience of illustration in connection with theseFigures, the numerals of the components shown in FIGS. 12 et seq. arenumbered, beginning with 100. Thus, certain elements in these Figureswill bear numerals differing from those utilized in the previousFigures.

Referring to FIG. 12, fastener 100 has a spear shaped tip 106dimensioned for forced entry into apertures 200a and 200b of retainer200. Bumps 103 help to retain fastener 100 within retainer 200 afterentry has been completed. In FIG. 12 bumps 103 are shown at twolocations. Bumps 103 are also provided on the rear face of fastener 100(not shown) to retain the fastener. Retainer 200 is securely positionedon retainer holder 300 having upstanding posts 300a, 300b, 300c, 300dwhich are dimensioned and configured to enter apertures 200a and 200b ofretainers 200 on the side opposite the fastener entry side. The retainerholder 300 provides a stable flat base for the retainer and disengagesfrom the retainer when the fastener portion engages the retainer. Asnoted hereinabove, during the operation of the instrument the fastenersare ejected from the fastener holding cartridge to mate with theirrespective retainers. Further details of novel retainer holdingcartridge 400 may be seen by referring to FIGS. 13A, 13B, 13C and 13D.

Retainer holding cartridge 400 is an elongated piece having two members402L and 402R longitudinally extending proximally from the distal end404 of the retainer holding cartridge 400. Left and right members 402Land 402R define a center longitudinal slot 406 for receiving thedistally moving knife member 32 described hereinabove. In oneembodiment, the proximal ends of members 402L and 402R have outwardlyprojecting pins 408L and 408R respectively, for pivotally mounting to asurgical fastener applying instrument. Alternatively, these pins couldbe eliminated. Each member 402L and 402R has a compartment 410comprising a relatively wide upper vertical walled channel 410a forseating one or more retainers, and a relatively narrow vertical walledlower channel 410b for mounting the retainer mounting elements. Thedifference in widths between the upper and lower channels definesshelves 412 on both sides of the compartment which support the retainersand act as a backstop. The lower channel 410b is adapted to holdretainer holders 300 in a frictional fitting such that they arefrictionally supported in an initial upper position wherein the retainerholders 300 are engaged with the retainers 200. The retainer holders 300are downwardly slidable when forced out of engagement with the retainers200 by the entering prongs of the fastener portions 100. Vertical guiderails 414 on the sides of the channels cooperate with slots 300e formedin retainer holder 300 to reduce the unwanted torquing of the retainerholders 300 and prevent the retainer holders 300 from moving distally orproximally. In the alternative, vertical post 400c may be provided toengage an aperture 301c in the retainer holder 300. See, also, post 51engaging aperture 53 as shown in FIG. 5. Alternatively, the retainercartridge 400 could be provided with both a vertical guide rail 414 oneach side to engage a respective side slot 300e in retainer holder 300,and a central post 400C as shown in FIG. 12 dimensioned to be receivedin aperture 301C in retainer holder 300.

Referring now to FIGS. 14A, 14B and 15, further details of the retainerholders are shown. Retainer holder 300 includes a base 302 having twointegrally connected substantially rectangular portions 302a and 302b,and a plurality of upright posts 304 for entry into the apertures on thebottom portion of the retainer as described hereinabove. The base has avertical notch 306 for slidably engaging guide rails 414 of the retainercartridge 400. Rounded corners 308 enable a smoother sliding fit betweenthe convex corner of one retainer mounting element being adapted to fitinto the concave corner of another mounting element. As noted, the widthof base 302 is such that the retainer mounting element 300 is retainedin the lower channel 410b by friction, or slight interference fit,although the retainer mounting element 300 is slidable in the verticaldirection. The uprights 304 ideally each have a sloped side 304a whichis angled slightly off the vertical such that the top of the upright isslightly narrower than the bottom. The tapering facilitates the entryand removal of the uprights from the retainer apertures.

Referring now to FIGS. 16A, 16B and 17, the retainers 200 are initiallyin the position illustrated in FIG. 16A. The retainer 200 is located inthe upper chamber 410a, and mounted on retainer holder 300 by means ofuprights or posts 304 which are inserted into the apertures 202 at thebottom of the retainer 200. A portion of the bottom of the retainer 200overlaps the edge of base 302 such that the overlapping portion rests onshelf 412.

Retainer holder 300 is slidably mounted within the lower channel 410b ofthe cartridge 400 with notch 306 in engagement with guide rail 414.

When the fasteners 100 are inserted into retainers 200, the barbed tips106 of the fasteners push down on the uprights 304, thereby pushing theretainer mounting element 300 down into a position where it is no longerin engagement with the retainer 200. The retainers 200 are supported byshelves 412 such that they are braced against downward movement. Upondisengagement with the retainer holders 300, the retainers 200 are freeto be lifted out of the cartridge 400 in engagement with the fasteners.

FIG. 17 illustrates in further detail, the operative portion of theapparatus for applying surgical fasteners, employing the fastener andcartridge system of the present invention as described hereinabove. Thefastener holding cartridge 500 contains fastener pushers 502, cam bar504, and optionally a knife 506. When actuated, the cam bar 504 is moveddistally, thereby contacting the sloped camming surface 502a of pusherelements 502 and urging the fastener portions downward into the retainercartridge 400 where fastener 100 engages its respective retainer 200. Asdescribed above, the cam bar 504 operates upon the pusher elements 502sequentially, first contacting the proximal end of each pusher element.As noted, because of this movement there may be a tendency for unwantedtorque to develop which might otherwise cause a relative clockwisepivoting of the fastener. Flat mounting element bases 302 and shelves412 help insure that the retainers 200 do not pivot appreciably.

In use, the apparatus is positioned such that a layer of body tissue issituated between the fastener holding cartridge 500 and the retainerholding cartridge 400. When the apparatus is actuated the fastener barbs106 will penetrate the tissue layer and lock into the retainer 200,thereby sealing the tissue. Although FIG. 17 shows the fasteners 100moving downwardly, the direction of movement to engage retainer 200 willobviously depend upon the orientation of the apparatus during use.

The apparatus as described hereinabove is preferably constructed as adisposable apparatus suitable for a single use. However, the apparatusis readily adaptable to a multiple use or non-disposable form merely bystructuring the fastener and retainer cartridges so as to be replaceablewithin their respective channels. In such case, replacement of the knifebar 32 with knife blade 35 is also desirable in order to assume preciseand accurate cutting of the tissue. The cam bars 34,36 could also bereplaceable along with knife 32. In the preferred form, the componentsare constructed of steel except for the cartridges, and the finger pad40 which are constructed of a suitable plastic material such as nylon orpolycarbonate. The preferred fastener and retainer are composed of abioabsorbable polymeric material, such as polymers or copolymers ofglycolide, lactide, p-dioxanone, polyester, polyamino acids and thelike, the preferred construction of which is shown and described in U.S.Pat. No. 4,932,960, which is hereby incorporated by reference.

What is claimed is:
 1. Apparatus for applying at least two rows oftwo-part surgical fasteners, each surgical fastener having a fastenerportion and a retainer portion, which comprises:a) a first sectionhaving a plurality of said fastener portions of said two-part fastenerssupported thereby, said fastener portions arranged in at least two rows;b) a second section engageable with said first section and having aplurality of said retainer portions of said two-part fasteners supportedthereby, said retainer portions arranged in at least two rows andsupported in positions opposite said fastener portions, said first andsecond sections being relatively movable to clamp body tissuetherebetween; and c) at least two cam bars movable within the firstsection and an actuating member for moving the at least two cam barslongitudinally for sequentially driving said fastener portions towardsaid retainer portions in a direction generally transverse to thedirection of movement of said at least two cam bars and into engagementwith each other.
 2. Apparatus according to claim 1 wherein a first rowof said at least two rows is disposed on one side of a generally centrallongitudinal axis and arranged in general longitudinal alignmenttherewith, and a second row of said at least two rows of fastenerportions is disposed on the other side of the longitudinal axis andarranged in general longitudinal alignment therewith.
 3. Apparatusaccording to claim 2 wherein a first row of said at least two rows ofretainer portions is disposed on one side of the longitudinal axis andpositioned opposite said first row of said fastener portions, a secondrow of said at least two rows of retainer portions is disposed on theother side of the longitudinal axis and positioned opposite said secondrow of said fastener portions.
 4. Apparatus according to claim 3 whereinone of said at least two cam bars is disposed on one side of thelongitudinal axis and positioned to sequentially drive said first row offastener portions, and a second of said at least two cam bars disposedon the other side of the longitudinal axis and positioned tosequentially drive said second row of fastener portions.
 5. Apparatusaccording to claim 1 further comprising a knife disposed between said atleast two cam bars for cutting the body tissue.
 6. Apparatus accordingto claim 5 wherein said first section comprises at least two rows ofapertures dimensioned and configured for frictionally detachably holdingsaid at least two rows of said fastener portions.
 7. Apparatus accordingto claim 6 wherein said second section comprises at least two rows ofretainer portion holders having means for supporting said retainerportions in position for reception of said fastener portions. 8.Apparatus according to claim 7 wherein each said retainer portion holdercomprises at least two upstanding posts extending generally transverselyrelative to a plane defined by said retainer portion holder, said atleast two upstanding posts dimensioned and configured to be receivedwithin correspondingly dimensioned and configured apertures formed insaid retainer portions to support said retainer portions within saidsecond section.
 9. Apparatus according to claim 8 wherein each saidretainer portion holder comprises two pairs of said upstanding posts, afirst pair of said upstanding posts positioned and dimensioned to enterinto first and second apertures of a first retainer portion, a secondpair of said upstanding posts positioned and dimensioned to enter intofirst and second holes of a second retainer portion.
 10. Apparatusaccording to claim 5 wherein said knife comprises a knife bar extendingin a generally longitudinal direction.
 11. Apparatus according to claim10 wherein said at least one cam bar and said knife bar are eachoperatively connected to a manually operable finger pad adapted forslidable longitudinal movement, whereby distal longitudinal movement ofsaid finger pad causes corresponding distal movement of said at leastone cam bar to sequentially advance said fastener portions intoengagement with their respective retainer portions and causes distalmovement of said knife bar to cut the body tissue adjacent the locationof the application of said fasteners.
 12. Apparatus according to claim11 wherein said knife bar comprises a knife edge at a distal endthereof.
 13. Apparatus according to claim 11 wherein said knife bar lagssaid at least one cam bar when said at least one cam bar is distallyadvanced.
 14. Apparatus for applying at least two rows of two-partsurgical fasteners to body tissue, each surgical fastener having afastener portion for piercing body tissue, and an apertured retainerportion for receiving said fastener portion, which comprises:a framedefining a longitudinal axis; a cartridge disposed within said frame forholding a plurality of said fastener portions in generally alignedrelation; a support member disposed within said frame and positionedopposite said cartridge for holding a plurality of said retainers inpositions opposite the respective fastener portion; means movable withinsaid cartridge for sequentially driving at least one of said fastenerportions and retainer portions into engagement with the other, saiddriving means adapted to drive said fastener portions in a directiongenerally transverse to said longitudinal axis of said frame; and anactuating member slidably mounted to said frame and adapted forreciprocal longitudinal movement relative to said frame, whereby distallongitudinal movement of said actuating member activates said fastenerportion driving means for driving said fastener portions into engagementwith said retainer portions.
 15. Apparatus according to claim 14 furthercomprising knife means for cutting body tissue adjacent the location ofthe applied fasteners.
 16. Apparatus according to claim 14, wherein saidcartridge is removably disposed on said frame.